Terminal block assembly



1961 E. R. KULKA 2,998,589

TERMINAL BLOCK ASSEMBLY Filed June 16, 1958 FIG. I

FIG. 2.

23 2b 24 I9 24 I 3b as I I8 H I I 27 I I 32 FIG. 3.

FIG. 4.

I INVENTOR.

U6N ,Q- m/L/(A 2,998,589 TERMINAL BLOCK ASSEMBLY Eugene R. Kulka, MountVernon, N.Y., assiguor to Kulka Electric Corp., Mount Vernon, N.Y., acorporation of New York Filed June 16, 1958, Ser. No. 742,259 2Clain1s.(Cl. 339-198) The present invention relates generally to improvements inelectrical connectors, and more particularly to an improved terminalblock construction.

Terminal blocks are widely used in all forms of electrical andelectronic equipment, and are made in a variety of sizes and types. Theconventional terminal block usually includes a body member formed ofinsulating material upon which a row or rows of terminals are mounted.The terminals are made of conductive metal and in some instances consistof threaded body members adapted to receive a binder screw or nut forreceiving the circuit terminal networks. The mounting of the terminalson the insulating block has heretofore presented a diffioult problemsince the terminal must present a flat contact surface flush with thetop of the block and its lower body portion is normally recessed withinthe bottom of the block. It has been customary to provide the terminalbody portion with a flange which is peened over a recessed surface ofthe block, but such procedure is costly and time-consuming and hasresulted in a finished article in which the terminals originally are orsoon become loose. This problem is particularly prevalent in themanufacture of miniature terminal blocks in which the metal terminalbodies are very small and the flanges to be peened over cannot be madeof sufficient thickness to properly support the terminal against thestresses to which it is subjected. In addition, in such miniatureterminal blocks, the bores receiving the terminal bodies are of verysmall diameter, making it difiicult to insert a tool for properlypeening over the terminal flange.

It is an object of the present invention to provide a terminal blockassembly having improved means for mounting the terminal body portionswithin the insulating block body.

In accordance with the invention, the improved terminal block assemblyincludes an insulating block body provided with a plurality of throughbores, a conductive metal terminal body portion insertible within eachof the bores, and a metal collar adapted to be rigidly connected to thebottom portion of the terminal body portion and engaging a shoulderwithin the bore to secure the terminal in mounted position.

Another object of the invention is the provision of a terminal blockassembly of the character described in which the metal collar is sizedto be force fitted on the terminal body portion in a simple andeconomical manufacturing step, while at the same time, providing astrong and rugged mount for the terminal.

Additional objects and advantages of the present invention will becomeapparent from a reading of the following description taken in.conjunction with the accompanying drawings, wherein:

FIG. 1 is a top plan view of an improved terminal block embodying thepresent invention;

FIG. 2 is a side elevational view thereof;

FIG. 3 is an enlarged detailed sectional view taken along line 3-3 ofFIG. 1; and

FIG. 4 is an enlarged detailed sectional view similar to FIG. 3, butshowing the parts in exploded form.

In accordance with a preferred embodiment of the present invention theterminal block includes an elongated body member or strip formed of anelectrically titted States Patent 2 Ice 2,998,589

Patented Aug. 29, 1961 insulating material and having a plurality oflongitudinally spaced bores formed therein separated by parallelupstanding walls, each of the bores having an enlarged bottom portion.Registering with each bore is the shank of a connector terminal, theshank being provided with a rectangular top flange which is disposedbetween adjacent walls and abuts the upper border of the bore, and isalso provided with an inwardly tapered lower portion disposed below theupper portion of the bore. collar under radial compression andcircumferential tension, achieved by a force fit, engages the shank andrests in the enlarged bore portion in abutment with a shoulderseparating the enlarged bore portion from the upper bore portion. Thecollar and top flange of the shank cooperate to secure the terminalmember in mounted position within the block.

Referring now to the drawings which illustrate a preferred embodiment ofthe present invention, the reference numeral 10 designates a terminalblock which is of the single screw type, or in other words has a singlerow of terminal elements mounting binder screws. Miniature terminalblocks are customarily made of this type. The terminal block .10includes an elongated body member or strip 11 formed of any suitableelectrically insulating material such as synthetic organic thermosettingmaterials or the like. The body member 11 is of substantiallyrectangular transverse cross section and has a pair of circular endmounting holes 12 formed therein to receive mounting bolts or screws(not shown) for mounting the terminal block on a support structure. Alongitudinal row of regularly spaced through bores 13 is also formed inthe body member 11 between the end openings 12. Each of the bores 13includes an upper portion 14 of circular transverse cross section,having a beveled top edge 16 and surrounded by an upper peripheral,horizontal border 17. Each through bore 13 also includes a lower portion18 of circular transverse cross section registering and communicatingwith the upper bore portion 14. The lower bore portion 18 is of largerdiameter than the upper portion 14 and forms therewith at its junctionan annular horizontal shoulder 19.

Located between successive through bores 13 and formed integral with thebody member are transverselyextending upstanding parallel partitionwalls 20 which project beyond the edges of the body member 11 and areprovided with depending sections 21 along the sides of the body member11. The edges of the walls 21 are rounded off as at 22. The partitionwalls 20 serve in the usual manner as barriers to separate the blockterminals and divide the block into individual stations for receivingindividual wiring, which stations are well in sulated from each other.As can be seen in FIG. 1, the top surface of the block body member 11between each adjacent pair of partition walls 20 forms an upperperipheral, lateral border 17 for each of the through bores 13. Theseupper peripheral borders 17 are squared or rectangular in shape, and areused in the mounting of the conductive terminals, as will presently bedescribed.

The connector terminal members are designated by the numeral 23 and eachincludes a longitudinal cylindrical body or shank 24 having an upperperipheral flange 26 of substantially square outline, the distancebetween opposing edges of the flange 26 being slightly less than thedistance between confronting faces of the partition walls 20. The lowerportion 27 of the shank 24 has a downwardly tapering wall. Dependingfrom the bottom of shank 24 and coaxial therewith is a soldering post 28delineated from the bottom of the shank 27 by an annular shoulder 29.The soldering post 28 terminates in the usual manner in an outwardlydirected lip 30 and is provided with an intermediate peripheral flange32.

A tapped axial bore 33 is formed in the shank 24 extending from the topto a point immediately above the bottom thereof. A headed screw 34engages the tapped bore 33 to complete the connector terminal member. Itis to be understood that the particular type of terminal member shown ispresented by way of illustration only and that other conventional typesof terminals may be employed in accordance with the invention. Forexample, the terminals may be made without soldering posts, or varioustypes of soldering lugs may be substituted. In addition, the terminalmay be of the well kno-wn navy type having an upstanding threaded shaftreceiving a binder nut.

Associated with each of the terminal members 23 is a locking collar 36of circular cross section having an inner diameter which inits-unstressed condition is slightly less than the outer diameter of themain portion of the shank 24 by an amount of the order of l to '5 milsand greater than the diameter of the underface of the tapered shanklower portion 27. The outer diameter of the collar 36 is appreciablygreater than the diameter of the upper bore portion 14 and slightly lessthan the diameter of the lower bore portion 18.

In assembling the terminal the shank 24 is inserted through the top of arespective bore 13 until its upper flange 26 nests between adjacentpartition walls 20 and rests upon the upper peripheral border 17surrounding said bore 13. The shank 24' is snugly received within theupper bore portion 14, the lower tapered shank portion 27 beinglocatedbelow the underface of the block body member 11. The collar 36 is forcefitted onto the shank 24 and is under radial compression andcircumferential tension being extended by the tapered portion of theshank. The collar 36 nests within the enlarged lower bore portion 18'with its upper face abutting the shoulder 19. The collar 36 is pressedtightly against the shoulder 19 so that it clamps the flange 26 againstthe marginal portion 17 of the block body top surface and securely holdsthe-terminal member 23 in mounted position. The straight edges of theflange 26 engage the bottom edges of the partition walls 22 to preventthe terminal body from rotating when the screws 34 are turned therein.

The assembly of the terminal block is preferably effected by insertingthe shank of the terminal member 23 into a corresponding aperture 13,locating a collar 36 on the tapered lower end of the shank 24 and thenceforce fitting the collar 36 onto the shank 24 by means of a tubular toolhaving an inner diameter slightly greater than the inner diameter of thecollar 36 and an outer diameter approximately equal to the outerdiameter of the collar 36. This may be performed economically byapplying the collars simultaneously to a plurality of the shanks bymeans of a suitable jig and ganged tool. I An example of the dimensionsand configuration of a commercial form connector terminal member 23formed of brass andwhich has been successfully employed is as follows:The shank 24 has an overall length of .314 inch and the diameter of itsupper portion is between .151 and .152 inch. The lower portion 27 of theshank 24 has aheight of .062 inch and-a taper of approximately 1 degree.The flange 26 is square having sides .250 inch long and is .045 inchthick. The height of the soldering post is approximately .281 inch andis of a diameter of .062 inch. The collar 36, when in normal unstressedcondition, has an inner diameter of between .149 inch and .150 inch, andan outer diameter of between .235 inch and 2.38 inch, and a height ofapproximately .125 inch. :lhie1 depth of the tapped bore 33 isapproximately .312 me While there has been described and illustrated apreferred embodiment of the present invention, it is apparent thatnumerous alterations and omissions may be made without departing fromthe spirit thereof.

What I claim is:

1. An improved terminal block comprising an elongated body member ofelectrically-insulating material and having a longitudinal row of spacedthrough bores, said body member having a flat upper border surfacesurrounding each of said bores, each of said bores having an upper boreportion and a lower bore portion of enlarged transverse cross sectionseparated from said upper bore portion by a peripheral shoulder, saidbody member having a plurality of upstanding transversely extendingpartition walls located between each of said bores and separating eachof said bores from each other, the flat upper border surfaces of saidbody member being located between said partition walls and the upperperipheral edge of said upper bore portion being beveled and contiguouswith the flat upper border surface circumjacent with said respectivebores, the outermost bores adapted to receive securing means forsecuring said body member to a support, a metal terminal member for eachof said bores that are intermediate of said outeremost bores, each ofsaid terminal members comprising a shank portion extending through andpositioned in the upper bore portion of each of said bores, a flatrectangular shaped flange extending laterally from the upper end of eachof said shanks, overlying the border surface of said body member andabutting the partition walls defining the flat upper border surface thatis in circumjacent relation to the respective bores, connector means atthe upper end of each of said shanks extending above said flat flangefor attachment of a lead wire to each of said terminal members, saidconnector means comprising a threaded axial bore in each of saidterminal members, each of said axial bores being provided with anupwardly directed opening in each of said shanks and a screw engagingthe opening in each of said threaded bores and projecting upwardly aboveeach of said flanges, a locking collar having an internal diameterslightly smaller than the external diameter of each of said shanks forcefitted under circumferential tension and radial compression upon each ofsaid shanks below each of said upper bore portions, each of said collarsresting in each of said lower bore portions and abutting each of theperipheral shoulders separating said upper bore portions and said lowerbore portions, each of said collars clamping each of said flangesagainst their respective border surfaces to prevent said lead wires frompulling said terminal members upwardly out of their respective bores.

2. An improved terminal block as in claim 1, wherein a soldering post isformed integral with the lower end of each terminal member in coaxialalinement therewith, each of said shanks having an inwardly taperedlower end projecting below each of said upper bore portions andproviding an annular shoulder that delineates said shank from saidsoldering post, a circular outwardly directed terminal lip portion onthe lower end of each of said soldering posts and a circular flangeintegral with and positioned on each of said soldering postsintermediate of each of said tapered shoulders and each of said terminallips.

References Cited in the file of this patent UNITED STATES PATENTS1,401,573 Wood Dec. 27, 1921 1,573,462 Thatcher Feb. 16, 1926 2,081,100Blakeslee May'l8, 1937 2,766,436 Luebking Oct. 9, 1956

